28 ALLEN 
SECTION I. INTRODUCTORY. 
I. INTRODUCTION. 
Tue blood-vascular system of fishes is no new subject. It 
has been carefully worked out for many groups. We have the 
memoirs of Miiller on Myxcne, T. J. Parker on JZlustelus, 
Hyrtl on the roaches, McKenzie on Ameiurus, Vogt on 
Salmo, Emery on fierasfer, Cuvier and Valenciennes on 
Perca, and the general account found in Stannius’ Anatomy. 
The object of this paper is to give a fairly complete account of 
the vascular system of Ophiodon elongatus (blue cod); and to 
make some comparisons with other members of the suborder 
LORICATI, the mailed-cheeked fishes. In a later paper I 
hope to go more into detail with the peripheral endings of the 
vessels in the organs of the viscera and those of special sense, 
as well as to take up the lymphatics. 
This group of fishes is distinguished by the extension of the 
third suborbital bone across the cheek as a stay to or toward 
the preopercle. In view of the wide variation in this group, 
Dr. Gill says (45)' that it is not a natural division. He, how- 
ever, divides this suborder into 8 different families, placing the 
Scorpenide (the rock fishes), as the most generalized, on 
account of their resemblance in form to the Serranide and 
Sparide ; and the Cottidz (the sculpins) are placed as the most 
specialized. Between these extremes come the family Hexa- 
srammide, placed nearer the Scorpznide than the Cottide. 
There are, however, many points of resemblance to the Cottidz 
to be found in their osteology, visceral organs, nervous and 
vascular systems. 
The subfamilies Hexagrammine, Ophtodontine, Zaniolepr- 
dine, and Oxylebiine, given by Jordan and Evermann (45, p. 
1864), are very strongly marked. Ophzodon and probably 
Zantolepis are about as closely related to Scorpenzchihys, a 
sculpin, as they are to Hexagrammos, and should be regarded 
as types of distinct families. 
The following species of fishes were studied. 
1 All figures in brackets refer to bibliography at the end of the paper. 
